Mechanical pencil



FIG. 1 is a front, bottom, left perspective view thereof;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a back elevation view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a left elevation view thereof. 

The ornamental design for a mechanical pencil, as shown and described. 